ufshcd_wait_for_register(9)

💅 ufshcd_wait_for_register(9) — bestie edition

okay so this is a page from the Kernel API Manual, and honestly? it's a little sleeper hit. it's one function, it does one thing, and it does it impeccably. we love a lowkey icon. 🎀

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✨ NAME ✨

ufshcd_wait_for_register — literally just sit there and wait for a register value to change. that's it. that's the whole gig. 💅

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🦋 SYNOPSIS 🦋

int ufshcd_wait_for_register (struct ufs_hba *hba , u32 reg , u32 mask ,
u32 val , unsigned long interval_us , unsigned long timeout_ms );

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🌸 ARGUMENTS 🌸

like a group chat, every member has a role and you cannot skip anyone:

• hba — the per-adapter interface. the main character of this whole operation, no cap. 👑
• reg — the mmio register offset. this is where we're looking, iykyk.
• mask — the mask to apply to the read register value. we're not reading the whole vibe, just the relevant bits ✨
• val — the value to wait for. the thing we're manifesting. 🕯️
• interval_us — polling interval in microseconds. how often we peek. respectfully. 🙈
• timeout_ms — timeout in milliseconds. the point where we have to accept it's not happening 😭

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💀 RETURN 💀

-ETIMEDOUT on error, zero on success.

so basically: 0 = slay, -ETIMEDOUT = the register ghosted us. periodt.

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🔥 SEE ALSO 🔥

okay bestie, buckle up, because this list is long — but every single one of these is a real reference and we do not skip a single name, fr fr.

Kernel file ./drivers/ufs/core/ufshcd.c

ufshcd_enable_intr(9), ufshcd_disable_intr(9), ufshcd_print_trs_all(9), ufshcd_print_pwr_info(9), ufshcd_get_intr_mask(9), ufshcd_get_ufs_version(9), ufshcd_is_device_present(9), ufshcd_get_tr_ocs(9), ufshcd_utrl_clear(9), ufshcd_utmrl_clear(9), ufshcd_get_lists_status(9), ufshcd_get_req_rsp(9), ufshcd_is_exception_event(9), ufshcd_reset_intr_aggr(9), ufshcd_config_intr_aggr(9), ufshcd_disable_intr_aggr(9), ufshcd_enable_run_stop_reg(9), ufshcd_hba_start(9), ufshcd_is_hba_active(9), ufshcd_pm_qos_init(9), ufshcd_pm_qos_exit(9), ufshcd_pm_qos_update(9), ufshcd_set_clk_freq(9), ufshcd_scale_clks(9), ufshcd_is_devfreq_scaling_required(9), ufshcd_pause_command_processing(9), ufshcd_resume_command_processing(9), ufshcd_scale_gear(9), ufshcd_devfreq_scale(9), ufshcd_hold(9), ufshcd_send_command(9), ufshcd_copy_sense_data(9), ufshcd_copy_query_response(9), ufshcd_hba_capabilities(9), ufshcd_ready_for_uic_cmd(9), ufshcd_get_upmcrs(9), ufshcd_dispatch_uic_cmd(9), ufshcd_wait_for_uic_cmd(9), __ufshcd_send_uic_cmd(9), ufshcd_send_uic_cmd(9), ufshcd_sgl_to_prdt(9), ufshcd_map_sg(9), ufshcd_prepare_req_desc_hdr(9), ufshcd_prepare_utp_scsi_cmd_upiu(9), ufshcd_prepare_utp_query_req_upiu(9), ufshcd_compose_devman_upiu(9), ufshcd_comp_scsi_upiu(9), ufshcd_upiu_wlun_to_scsi_wlun(9), ufshcd_queuecommand(9), ufshcd_dev_cmd_completion(9), ufshcd_exec_dev_cmd(9), ufshcd_init_query(9), ufshcd_query_flag(9), ufshcd_query_attr(9), ufshcd_query_attr_retry(9), ufshcd_query_attr_qword(9), ufshcd_query_descriptor_retry(9), ufshcd_read_desc_param(9), struct uc_string_id(9), ufshcd_read_string_desc(9), ufshcd_read_unit_desc_param(9), ufshcd_memory_alloc(9), ufshcd_host_memory_configure(9), ufshcd_dme_link_startup(9), ufshcd_dme_reset(9), ufshcd_dme_enable(9), ufshcd_dme_set_attr(9), ufshcd_dme_get_attr(9), ufshcd_dme_rmw(9), ufshcd_uic_pwr_ctrl(9), ufshcd_uic_tx_eqtr(9), ufshcd_send_bsg_uic_cmd(9), ufshcd_uic_change_pwr_mode(9), ufshcd_get_max_pwr_mode(9), ufshcd_dme_change_power_mode(9), ufshcd_change_power_mode(9), ufshcd_config_pwr_mode(9), ufshcd_complete_dev_init(9), ufshcd_make_hba_operational(9), ufshcd_hba_stop(9), ufshcd_hba_execute_hce(9), ufshcd_link_startup(9), ufshcd_verify_dev_init(9), ufshcd_setup_links(9), ufshcd_lu_init(9), ufshcd_sdev_init(9), ufshcd_change_queue_depth(9), ufshcd_sdev_configure(9), ufshcd_sdev_destroy(9), ufshcd_scsi_cmd_status(9), ufshcd_transfer_rsp_status(9), ufshcd_uic_cmd_compl(9), ufshcd_compl_one_cqe(9), __ufshcd_transfer_req_compl(9), ufshcd_mcq_compl_pending_transfer(9), ufshcd_transfer_req_compl(9), ufshcd_disable_ee(9), ufshcd_enable_ee(9), ufshcd_enable_auto_bkops(9), ufshcd_disable_auto_bkops(9), ufshcd_force_reset_auto_bkops(9), ufshcd_bkops_ctrl(9), ufshcd_exception_event_handler(9), ufshcd_quirk_dl_nac_errors(9), ufshcd_abort_all(9), ufshcd_err_handler(9), ufshcd_update_uic_error(9), ufshcd_check_errors(9), ufshcd_tmc_handler(9), ufshcd_handle_mcq_cq_events(9), ufshcd_sl_intr(9), ufshcd_intr(9), ufshcd_issue_tm_cmd(9), ufshcd_issue_devman_upiu_cmd(9), ufshcd_exec_raw_upiu_cmd(9), ufshcd_advanced_rpmb_req_handler(9), ufshcd_eh_device_reset_handler(9), ufshcd_try_to_abort_task(9), ufshcd_abort(9), ufshcd_process_probe_result(9), ufshcd_host_reset_and_restore(9), ufshcd_reset_and_restore(9), ufshcd_eh_host_reset_handler(9), ufshcd_get_max_icc_level(9), ufshcd_find_max_sup_active_icc_level(9), ufshcd_scsi_add_wlus(9), ufshcd_create_device_id(9), ufshcd_quirk_tune_host_pa_tactivate(9), ufshcd_quirk_override_pa_h8time(9), ufshcd_add_lus(9), ufshcd_get_op_mode(9), ufshcd_probe_hba(9), ufshcd_async_scan(9), ufshcd_set_dev_pwr_mode(9), ufshcd_suspend(9), ufshcd_resume(9), ufshcd_system_suspend(9), ufshcd_system_resume(9), ufshcd_runtime_suspend(9), ufshcd_runtime_resume(9), ufshcd_remove(9), ufshcd_set_dma_mask(9), ufshcd_devres_release(9), ufshcd_alloc_host(9), ufshcd_init(9)

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and that's the whole page, bestie. no notes. 🫶

sign-off szn: this lil masterpiece lives in <pink>./drivers/ufs/core</pink>, dated October 2026 — go drink some water and go touch a register 💖✨🌈🍓